Aim. To study the involvement of APOC1 rs445925 and rs4420638 single nucleotide polymorphisms (SNP) in the development of occlusive peripheral arterial disease (PAD) of lower extremities.Material and methods. The study included 1278 people, including 630 patients with occlusive PAD and 648 relatively healthy individuals. Genotyping of APOC1 rs445925 and rs4420638 SNPs was performed using the MassARRAY-4 genomic mass spectrometer. The analysis of the association of alleles, genotypes, haplotypes and diplotypes with the risk of occlusive PAD was performed using the statistical programs SNPStats, PLINK, v1.9 and STATISTICA 13.3. The adaptive permutation test was used to assess statistical significance of associations (Pperm).Results. The rs445925-A (Pperm=1,0×10-6) and rs4420638-G (Pperm=0,006) alleles, as well as the rs445925-G/A-A/A (Pperm=1,0×10-6) and rs4420638-A/G-G/G (Pperm=0,006) genotypes were associated with an increased risk of occlusive PAD. The rs445925 polymorphism was also associated with the blood cholesterol level in patients with occlusive PAD (Pperm=0,04). The rs445925A-rs4420638A and rs445925A-rs4420638G haplotypes, as well as three APOC1 diplotypes, showed a pronounced relationship with a predisposition to occlusive PAD. In particular, the rs445925G/A×rs4420638A/A (odds ratio (OR) 6,59, 95% confidence interval (CI) 4,20-10,35, P=2,4×10-19) and rs445925G/A×rs4420638A/G (OR 4,24, 95% CI 2,23-8,03, P=2,0×10-6) diplotypes were associated with an increased risk of occlusive PAD. The rs445925G/G×rs4420638A/A diplotype had a protective effect on the disease development (OR 0,26, 95% CI 0,20-0,35, P=1,3×10-20). Associations of haplotypes with the severity of peripheral arterial stenosis of various locations were also revealed (P<0,05).Conclusion. The study results established for the first time that APOC1 rs445925 and rs4420638 polymorphic variants are part of a genetic predisposition to occlusive PAD and have a significant effect on the severity of peripheral arterial stenosis. The molecular mechanisms underlying the identified genotypic associations can affect not only lipid metabolism disorders, but also the proliferation of immunocompetent cells, platelet activation and aggregation processes, inflammation and apoptosis.